i have a gutted cat, will this make the cel go off? If the rear o2 is the culprit, will it hurt performance?

haha yeah, generally when you start screwing with the cat your gonna throw a CEL. the only one that makes a difference in performance is the upstream o2 sensor. the one thats throwing the cel is the one after the cat. this sensors only purpose is to alert you when the cat needs replacing/isnt working properly. course, when you knock all the shit outt one it generally dosent work properly lol so it throws a cel telling you that its not working....well DUH! :P it has nothing to do with performnace, so dont worry about it. oh, and ill bet your wish you hadnt done that in a few weeks. with us being NT's it really kills low end power and we dont really gain that much back in the top end either. i punched out mine, but soon went and got a hi flo cat....even that dosent do very much...kinda wished i woulda left my stock kitty alone...oh well...hindsight is always 20/20

I felt a good gain with the high flow, a much need reduction in restriction... but then again I have cams.

You will get a CEL with a test pipe or hollowed cat, you can find an O2 simulator or whatever it's called to plug into the wiring harness to fool the ECU.



15.9 @ 86.7mph

Injen CAI, 55mm TB, P&P Intake, Crower Cams, Hooker Header, ERT/Catco Cat, GS-T Muffler, AFX UDP, Crane Ign Amp, S-AFC

isnt there also sum mod you can do with some resistors to fool the ecu remember reading that somewhere

yah its a resistor you can buy at radioshack and splice it in on one of the wires.http://www.zx2racing.com/mods/mods_mil.htm .Go to radioshack and find a 1 Megaohm, 1/4 watt resistor, and put that in line with the black wire of the REAR o2 sensor, the one after the cat

just splice it inline with the black o2 wire under the drivers seat, i have mine in, so i can run a testpipe at the track without throwing a code